Some pharmaceutical formulations are provided in a lyophilized powder form within a sealed vial for mixing with a liquid prior to administering the formulation to a patient. Mixing of the lyophilized formulation with its carrier liquid involves injection of the liquid into the vial using a syringe with a needle that punctures through a stopper that seals the opening of the vial. The mixed formulation is then aspirated and transferred into another carrier volume, such as a sealed bag of liquid to be suspended for delivery to a patient.
Lyophilization of the formulation is generally carried out in specialised lyophilization apparatus that freezes a liquid form of the formulation at low temperature and pressure, for example at about 0.05 mbar and about −10° C., and converts the formulation to lyophilized form by sublimation. The lyophilization apparatus generally comprises a condenser to condense water vapour sublimated from the formulation.
In some cases, a solution formulation is preferred. However, some solutions are oxygen sensitive and can suffer from stability problems with the formulation due to the inability to remove enough oxygen gas from the headspace of the vial and dissolved oxygen in solution prior to sealing it.
It is desired to address or ameliorate one or more shortcomings or disadvantages associated with existing preparation methods and systems, or to at least provide a useful alternative thereto.